Typically, exposed photographic film is spliced together for development and printing to facilitate handling of the film in automated equipment. Individual film rolls are removed from their containers, called cartridges or cassettes, and the resulting film strips are coupled together end-to-end with splices. The coupled strips form a long ribbon that is threaded and follows a sinuous path through processing equipment, into and out of developing solutions and drying chambers. Most of the processing steps are completed in the dark. Such rough handling, and the severe consequences of a break, require a secure attachment at every splice. The splices include a tough paper or plastic backing coated with a thermal adhesive. Usually the splices are applied to the film strips with heat and pressure.
In the case of 35 mm film, after processing, the film is cut to remove the splices and again to divide the film strip corresponding to a complete customer order into smaller segments, such as four, five or six negative frames per segment. This is anticipated during film manufacture, when leaders and trailers at the ends of the film strips are provided with extra material.
In a newly introduced photographic system, generally referred to as the Advanced Photo System, the film strips are returned after processing to the same cartridge that was used for loading the film into the camera. The splice may still be removed by cutting, but the cut film strip must then be re-shaped and reinserted into the cartridge for return to the customer. Although cutting is a simple approach for removing splices, it obviously damages and shortens the film compared to its manufactured state. These Advanced Photo System film strips have a special configuration at their leading and trailing ends. At the trailing end the shape facilitates attachment of the film to a spool inside the cartridge. At the leading end the shape reduces friction at the cartridge exit to facilitate thrusting out of the film for viewing or reordering prints. When the film is cut, the configuration and its accompanying features either are lost, or must be included in the cutting die.
Film strips typically are manufactured with extra material to accommodate splice removal during processing. Again the approach is simple, but adds material expense, including silver, a precious metal. This material then must be disposed of after processing. The amounts are small when compared to a single film strip, but build up at the photofinishing level. Silver is a heavy metal that requires special disposal procedures. For the foregoing reasons, therefore, it is desirable to provide apparatus and methods for removing the splice tape from film strips after the processing steps without damaging the leading and trailing ends of the film strips.
In commonly assigned U.S. Pat. No. 5,373,339, a non-destructive, automated method and apparatus for desplicing photographic film is shown in which a film splice and splice pick-up web are positioned between a vertically reciprocating heat shoe and a platen. The heat shoe is pressed down to the splice to heat the thermal splice adhesive thereby allowing the film strips to be pulled free of the splice when the heat shoe pressure is removed. In order to retain the detached splice tape in position over the splice pickup web while the films are pulled apart, a retaining rod aligned with the splice space between the two film strips is pressed up through the platen surface to hold the splice tape against the heat until the films have been removed. Once the films are removed, the heat shoe and retaining rod are then lowered to tack the splice tape to the splice pickup web and the web is advanced to remove the splice tape from the area of the heat shoe. While satisfactory for its purpose, it requires accurate positioning of the film in the heat shoe area to ensure proper alignment of the retaining rod with the splice space between the film strips. Additionally, if the film strips are contiguous, without any space between the film strips, it requires that the film strips be cut to separate them from each other, which damages the film strip ends and leaves the splice tape on the film ends, an unsatisfactory situation, particularly at the leader end which can interfere with smooth thrusting of the film strip from its storage cartridge.
In copending application Ser. No. 08/819,402, filed Mar. 17,1997, now U.S. Pat. No. 5,807,459, apparatus and method for separating spliced strips of photographic film is disclosed which addresses the foregoing concerns. While effective, the disclosed apparatus is somewhat cumbersome to operate and thus there is a need for slightly more automated equipment that facilitates the desplicing function with a minimum of handling by the operator. The present invention addresses this need.